The present invention relates to an apparatus for forming a coating film by applying a coating solution onto a substrate to form an insulating film such as an interlayer dielectric film in a manufacturing step for a semiconductor device.
A manufacturing process for a semiconductor device includes a step of forming an interlayer dielectric film on a metal wiring layer made of aluminium or copper, or between metal wiring layers. The interlayer dielectric film is known to be formed by various methods including a Sol-Gel method, a SiLk method, a SPEED FILM method, and a FOx method.
In the Sol-Gel method, a sol (colloid solution) having TEOS (tetraetoxysilane; Si(OC2H5)4) dispersed in an organic solvent, is spin-coated on a surface of a semiconductor wafer. Then, the coated sol is changed into a gel (Gel processing). Furthermore, the solvent in the coating film is replaced with another solvent (solvent exchange processing), dried and baked. Through these steps, a desired interlayer dielectric film is obtained. In the gelation step, for example, ammonia is used as a chemical solution. In the solvent exchange processing, ammonia or hexamethyldisilazane (HMDS) is used as the chemical solution.
A chemical solution supply source of a conventionally used apparatus is arranged away from a process section so as not to have an adverse effect upon the process. Therefore, a long pipe is required for supplying a chemical solution from each supply source to the process section. However, if the pipe is long, the chemical solution present in gaseous form or vapor form is easily condensed in the pipe. As a result, the process may be adversely affected.
Since the waste liquid/exhaust gas line passes under the process section in a conventional device, the waste solution or chemical components contained in an exhaust gas may have an adverse effect upon the process in the process section. Furthermore, from a safety/health point of view, it is not preferable that the waste liquid/exhaust gas line is arranged under the process section.
In the SiLK method, SPEED FILM method, and FOx method, a coating solution is applied to a cooled wafer, heated, cooled, and further heated and cooled in an atmosphere low in oxygen concentration. Through these steps, the coating film is cured to obtain an interlayer dielectric film.
In the meantime, different types of interlayer dielectric films are sometime required to be formed on the same wafer. To describe more specifically, an interlayer dielectric film having a high relative dielectric constant (high K) and an interlayer dielectric film having a low relative dielectric constant (low K) are required to be formed on the same wafer in some cases. In such cases, a method suitable for a type of interlayer dielectric film is selected from the Sol-Gel method, SiLK method, SPEED FILM method, and FOx method. Based on these technical background, a single device capable of forming various types of interlayer dielectric films has been strongly demanded. Furthermore, a device is required for forming an interlayer dielectric film with a high throughput in accordance with any one of the methods.
An object of the present invention is to provide an apparatus for forming a coating film capable of forming various types of the coating films with a high throughput in a single apparatus.
Another object of the present invention is to provide an apparatus for forming a coating film, having no adverse effect on a process when a chemical solution is supplied to the process section and an exhaust gas and a waste liquid are discharged from the process section.
According to the present invention, there is provided an apparatus for forming a coating film comprising; a process section for applying a series of processes for forming a coating film, to a substrate; and a common transfer mechanism for transferring a substrate in the process section.
The process section comprises a cooling unit for cooling a substrate; a coating unit for applying a coating solution containing a first solvent to the substrate to form a coating film; an aging unit for changing the coating film formed in the coating unit to a gel-state film when the coating film is formed in a sol-state; a solvent exchange unit for bringing a second solvent, which differs from the first solvent in composition, into contact with the coating film to replace the first solvent contained in the coating film with the second solvent; a curing process unit for heating and cooling the substrate under an atmosphere low in oxygen concentration, thereby curing the coating film; and a heating unit for heating the coating film formed on the substrate.
Furthermore, the apparatus comprises a carrier station provided next to the process section for loading/unloading an unprocessed substrate and a processed substrate into/from the process section; and a transfer section for transferring a substrate between the carrier station and the process section.
The process section may have at least two coating units.
The process section has a first coating unit for coating an adhesion promoter solution low in viscosity on a substrate and a second coating unit for coating an interlayer dielectric film formation solution high in viscosity on a substrate.
The process section has at least two aging units and at least two curing process units.
The solvent exchange unit, the coating unit, the aging unit are arranged next to each other.
Furthermore, the apparatus may have a side cabinet provided next to the process section.
The side cabinet comprises a bubbler for generating a vapor of a chemical liquid and supplying the vapor of a chemical liquid generated, to the aging unit; a trap section for trapping a waste and a discharge gas derived from the solvent exchange unit, the aging unit, and the coating unit; and a drain section for discharging a liquid component separated from a gaseous component in the trap section.
In this case, the bubbler is arranged next to the heating unit.
It is preferable that the process section have a first coating unit for coating an adhesion promoter solution low in viscosity, on a substrate and a second coating unit for coating an interlayer dielectric film solution high in viscosity, on the substrate; and each of the first coating unit and the solvent exchange unit is arranged next to the side cabinet.
The side cabinet is preferably isolated from the carrier station by the process section.
The second coating unit preferably has temperature control means for controlling a temperature of the interlayer dielectric film forming solution.
The solvent exchange unit has temperature control means for controlling the second solvent.
According to the present invention, there is provided an apparatus for forming a coating film comprising, a process section for applying a series of processes for forming a coating film, to a substrate; and a common transfer mechanism for transferring the substrate in the process section.
The process section comprises a first process unit group including a coating unit for coating a coating solution containing a first solvent on the substrate; and a solvent exchange unit for bringing a second solvent, which differs from the first solvent in composition, into contact with the coating film to replace the first solvent in the coating film with the second solvent, and a second process unit group including a cooling unit for cooling the substrate; a heating unit for heating the substrate; an aging unit for changing the coating film into a gel-state film if the coating film is formed in a sol state in the coating unit; and a curing process unit for heating and cooling the substrate under an atmosphere low in oxygen concentration to cure the coating film.
The common transfer mechanism is provided next to the first and second process unit groups, for transferring a substrate to at least a coating unit, solvent exchange unit, cooling unit, heating unit, aging unit, and curing process unit.
According to the present invention, there is provided an apparatus for forming a coating film comprising, a process section for applying a series of processes for forming a coating film, to a substrate; a common transfer mechanism for transferring the substrate in the process section; and a chemical liquid section provided next to the process section while isolated therefrom.
The process section comprises a coating unit for coating a coating solution of a sol state having particles or colloid dispersed in a solvent, onto the substrate; an aging unit for changing the particles or colloid in the coating film into a gel; and a solvent exchange unit for replacing a solvent in the coating film with another solvent.
The chemical liquid section has a chemical liquid supply system for supplying a chemical liquid to each of the aging unit and the solvent exchange unit; and a waste liquid/gas process system for discharging a waste liquid and an exhaust gas derived from the aging unit and the solvent exchange unit.
The solvent exchange unit, the coating unit and the aging unit are arranged next to each other.
The chemical liquid section generates a vapor of the chemical liquid and has a bubbler for supplying the vapor of the chemical liquid to the aging unit.
The chemical liquid section has a tank for storing the chemical liquid to be supplied to the solvent exchange unit.
The chemical liquid section may have a drain tank for trapping a waste discharged from the aging unit; and a trap section communicating with the drain tank and the solvent exchange unit for separating the waste discharged from the solvent exchange unit into a gaseous component and a liquid component, and sending the liquid component separated, to the drain tank.
According to the present invention, there is provided an apparatus for forming a coating film comprising, a process section having at least a coating process unit for coating a coating solution onto a substrate, and a chemical solution process unit for processing a coating film formed in the coating process unit, with a chemical solution; and a chemical liquid section arranged next to the process section while isolated therefrom.
The chemical liquid section has a chemical liquid supply system for supplying a chemical liquid to the chemical liquid process unit; and an exhaust gas/waste process system for processing a waste liquid and an exhaust gas derived from the chemical liquid process unit.
In a case where an interlayer dielectric film is formed in the Sol-Gel method, a substrate is transported sequentially to the cooling unit, coating process unit, aging unit, solvent exchange unit, and heating unit.
In a case where an interlayer dielectric film is formed by the SiLK method and SPEED FILM method, a substrate is transferred to the cooling process unit, coating process unit (adhesion promoter coating), cooling process unit, coating process unit (main chemical liquid coating), heating unit, cooling unit, and curing process unit.
In a case where an interlayer dielectric film is formed by the FOx method, a substrate is transferred sequentially to the cooling unit, coating unit, heating unit, cooling unit, and a curing unit.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.